Apparatus for rotary drilling



March 10, 1942. J. A. zUVBLlN 2,275,832

Alf-PARATUS 15011 ROTARY DRILL'ING March 10, 1942. J. A. .zUB| 1N 2,275,832

APPARATUS FR ROTARY DRILLI'NG Filed@ Jan. 29, 1941 2 Sheets-Sheet 2 1MM la j \30 f' 'l/32' In f A I I l .2 v s h Pate-med Mar. 1o, 1942 Y UNITED STATES PATENT OFFICE APPARATUS FOR ROTARY DRILLING John A. Zublin, Los Angeles, Calif. Application January 29, 1941, Serial No. 376,538

' (ci. 25e-c1) 11 Claims.

This invention relates to new and useful' improvements in apparatus for rotary drilling oil wells, or the like.

It is the present practice in rotary'drilling to employ bits which have two or more cutters of the roller, cone, or drag type. These cutters collectively provide a working face which is usually at, or substantially flat, and is symmetrical with, as well as normal to, the axis of the hole. Consequently, the active edges of the cutters, be they the teeth of rollers or cones or the wings of drag bits, all simultaneously engage the bottom of the hole, and the shape of this bottom will correspond with the shape of the aforesaid collective working face of the cutters.

When a hole must be dug through hard formations having great crushing strength, 'this simultaneous engagement of so many cutting edges with the bottom of the hole makes penetration difficult, and it can only bel accomplished by employing heavy drill collars and by applying much drilling weight to the bit.

`In drilling holes with a bit that produces a bottom corresponding in shape with the collective working face of the cutters, the various cutting edges all attack the formation at the samey angle. This is not a desirable action, particularly with roller or cone cutters, because the teeth of the diierent cutters have a tendency to track, which will wear out the teeth without making the desired progress.

vIt is the primary object of this invention to provide apparatus for rotary drilling oil wells, or the like, in which the number of cutting edges simultaneously in contact 'with the formation at any one time is materially reduced with the result that hard formations may be drilledwhile using considerably less weight.`

A still further important object of the invention is to provide apparatus for rotary drilling of this specification and in which like numerals are employed to designate like parts throughout the same, Y

Figure 1 is a vertical sectional view of rotary drilling apparatus embodying this invention,

Figure 2 is a transverse sectional view taken on line 2-2 of Figurel,

Figure 3 is a transverse sectional view taken Y on line 3-3 of Fig. 1,

Figure 4 is a longitudinal vertical sectional view of a slightlymodied form of rotary drilling apparatus embodying this invention, and

Figure 5 is a longitudinal vertical sectional view of a still further modified form` of drilling apparatus.

In the drawings, wherein for the purpose of illustration are shown the preferred embodiments of this invention, andparticularly referring to Figs. 1 to 3,-inclusive, the reference character 6 designates the oil well,v or other hole, being produced by the disclosed rotary drilling apparatus. This drillingapparatus includes a shank 1 having the conventional reduced, threaded end 8 to enable the apparatus to be coupled to the conventional drill collar of the drill pipe, both of which `are not shown. The lower portion of this shank 'I is hollowed out to form a socket9 ventionally employed rotary mud water.

which will product g'reater footage for each bit employed by maniplating the bit in the hole so as to provide ani increasedV reserve of drilling In the accompanying drawings forming a part y wall of the socket 9. It will be appreciated that This rotary drilling apparatus is completed bythe bit unit whichincludes the body Vlli on which the -desired number of roller cutters I'I and I8 are mounted. The remainder of the bit body includes a pin I9 which is fitted for axial sliding movement in the socket 9 of the shank 1. The periphery of this pin I9 is generally cylindrical in shape but is provided with an annular ball race 20 that is of considerably greater Width than the ball race I2 formed in the inner the greater width of the inner ball race 20 will permit the pin I9 of the bitbody-"IG to partake of axial movement relative. to the 'socket 9 of the shank, and this relative movement will be limited by the annular, series of balls I2 engaging the opposite sides of the extended race` 20.

At the base of the pin I9, the bit body I6 is providedwith a circular series of clutch teeth 2| which are intended to cooperate with the clutch teeth I0 of the shank I when the shank and bit body are arranged as is shown in Fig. 1, that is, when the series of balls I2 are cooperating with the lower side portion of the extended inner race 20. These cooperating clutch teeth I0 and 2 I, when properly engaged, will cause the bit body I6 to be driven by the shank 1 when it in turn is rotated by the drill collar and drill pipe. The bit body I6 is provided with a duct 22 which cooperates with the duct I5 of the shank 1 for delivering the rotary mud hto the aforementioned roller cutters.

It will be noted by inspecting Fig. l that the axis of the hole E and the axis of the threaded upper end 8 of the shank 1 are represented by the dash line 23, while the axis -of the socket 9 of the shank and the axis of the 'pin I9 of the bit body are represented bythe dash line 24. It is apparent, therefore, that the bit axis is tilted or angularly arranged with respect to the axis of the hole beingproduced by the bit. This angle may be varied as desired, but it has been 'determined that an angle of approximately 4 will be preferred.

The roller cutters II and I8, disclosed in Fig. 1, are of more or less conventional form. Each one of the two illustrated cutters I is provided with a cutting face, or a series of cutting teeth 2-5 which will determine the shape of the sides of the hole 6. A second cutting face, or series of cutting teeth, 26 is provided on the periphery of each one of the roller cutters II and these teeth will help to make the bottom of the hole.

the shank I to be rotated to any desired degree relative to the bit. After this angular adjustment has been accomplished, the drill pipe with its shank 'I may be lowered and the two sets of clutch teeth I0 and 2| will re-engage each other.

It will be appreciated, however, that the relative positions of the bit and the shank have now been changed. Any desired number of different relative positions may be provided by employing the proper number of teeth I0 and 2| for the two clutch portions. If We assume that the drill pipe and its shank I have been rotated a few vdegrees in a counter-clockwise direction when viewed from above, the bottom dead center of the illustrated inner cutter I8 will be lowered with respect to the bottom dead center of the right-hand outer cutter I'l and the bottom dead center of the left-hand outer cutter I1 will approach more nearly the plane occupied by the bottom dead -center of the right-hand outer cutter I1. Also, the inner cutter I8 which is not shown will have its bottom -dead center elevated above the bottom dead center of the illustrated inner cutter I8.

With the various cutters assuming these new relative positions, the shape of the bottom of the Only one roller cutter I8 is illustrated in Fig. 1,

but several similar cutters will be provided to ll the open space between cutters I1 so as to remove the center portion of the hole. A The cutters of 'this' type are provided with a series of teeth 21. which will cooperate with the teeth 26 of the cutters I'I for making the bottom of the hole. Y

With the axis of the bit tilted relative to the axis of the drill hole and with the bit body clutched to the shank in the position illustrated in Fig. 1, the right-hand roller cutter Il will be the only one of these two side wall producing cutters which will be arranged in a cutting position. In other words, the left-hand roller cutter II will be held out of engagement with both the side wall and the bottom of the hole and will be idle. The two inner cutters I8 will. be arranged so as to penetrate the formation being worked uponto an equal extent or degree. Thisl equal penetration of the inner cutters I8 results from the particular arrangement of the bit body I6 with respect to the shank .1.

If we now assunie that the operator is watching the progress made by the bit and decides that the cutting efciency of the right-hand roller, when operating inthe illustrated position,

' has been reduced to a predeterminedF extent, he may then decide that it is time to bring about an adjustment between the shank 'I and the bit body I6. This adjustment is accomplished by raising the drill pipe-to a suillcient extent to hole will be diiferent from that illustrated ln Fig. l and the two inner cutters I8 will penetrate the formation to a different extent ordegree. If

the change in relative positions lbetween the bit body |6 and the shank have been suiiicient, both of the outer cutters I'I will penetrate the formation at the bottom of the hole but the right-hand outer cutter I1 will still penetrate to a greater extent than the left-hand outer cutter. If the relative adjustment has not been as much as was just assumed, the right-hand outer cutter II still will be the only one which is operating to chafe the side wall of the hole and to penetrate the outer or marginalportion of the bottom of the holeA and the left-hand outer cutter I1 still will be idle.

It is believed from this explanation of. a single adjustment of the bit relative to the shank that persons skilled in the art will appreciate the extent to which the bit may be caused to assume different cutting positions and to attack the formation, at different angles. 'I'hese adjustments will operate to prevent tracking of the teeth of similar cutters, as well as the teeth of all of the cutters and a considerable amount of tooth surface will be maintained in reserve at all times. Of course, the operator will continue to repeat his adjustment of the shank I relative to the bit body I6 until he has exhausted the effectiveness of the bit. It then will be necessary to pull out thedrill pipe and substitute a new unit of the type illustrated in Fig. 1.

In Fig. 4 there is disclosed rotary drilling apparatus of the same general. type as that illustrated in Fig. 1 but a different form of clutch clear the two sets of clutch teethv Il! and 2|.

Sudlcient relative ,movement to accomplish this desired result is permitted by the inner ball race 20. Due to the weight of the bit body I8 and its several cutters |I and I8, the bit will remain stationary while -the shank 1, and the drill pipe, are elevated. After the cluh teeth |`0 and 2| have been disconnected, the operator may cause connection is provided between the shank and the bit body while cone cutters instead of roller cutters are employed. The shank, in Fig. 4, is designated by the reference :character 28. This shank is provided with a pin 28 that includes a ball race portion 3|) and a clutch portion 8|. The ball race portion 30 cooperates with the circular series of retaining balls 32 in the same manner as the ball race 20 of the bit body shown in Fig. 1. The clutch portion 3| of the shank is formed exteriorly so as to provide any desired number of flats.v Four of such flats are repre- `sented by the disclosure of Fig. 4`but it-will be cutters includes a side wall forming set of teeth 35 and a bottom forming set of teeth 36.

' I'he upper portion of the bit body is socketed y in' a manner to provide a cylindrical socket portion 31 and a clutch portion 38; The cylindrical portion is provided with a ball race 39 that cooperates in an obvious manner to receive thel circular series of balls 32; These balls are inserted through the hole 40 which is normally closed bythe threaded plug 4|. The clutch portion 33 of the socket, ofcourse, is formed with the same number of i'lats as is provided on the clutch portion 3| of the shank pin.

A suitable duct 42 is provided inthe shank 28, including its pin portion, to deliver the rotary mud water to the relatively short duct 43 formed in the bit body 33. The rotary mud water'will reach the cutters through vthese two cooperating ducts. The shank 28 is provided with the conventional, threaded upper end 44 for connection with the drill collar kwhich is carried by the drill pipe.

The axis of the hole 6 and the reduced upper I end portion 44 of the shank 28 is represented by the dash line 45. The axis of and the shank pin portion are represented by the dash line 46. It will be seen, therefore, that the' axis of the bit is tilted relative to the axis of the hole.

the bit bOdy 33 the plug 60. As was the case with the previously described units, thewide ball race 56 cooperates with 'the retaining balls so that these two elements adjusted.

'.Ilhe bit disclosed in this Fig. 5 is of the conmay be angularly ventional drag typel which includes a threaded upper end 6| to be coupled to the threaded portion 56 of the bit body. This bit includes a suitable number of cutting wings 62 which are provided with bottom forming edges 63 and side wall forming edges 64.

'If desired, the weight of the bit body 53 and the drag bit may be relied upon to disconnect the clutch parts 5| and 55 when the drill pipe and the drill shank are lifted. Itis believed to be more desirable, however, to employ a heavy compression spring 65 vfor breaking the clutch connection when the drill pipe is elevated. This compression spring is located in a pocket `66 formed in the shank 41 and bears against the inner end of this pocket and a suitable washer 61 which is applied tothe inner end of the threaded part 6| of the bit.

A suitable duct 68 is formed in thev shank 41 to deliver the rotary mud to the duct of the drill This rotary drilling unit may be employed in l the -same'ma'nner as the unit illustrated in Fig. l; i. e., the angle ofA attack of the active cone cutter or cutters with respect to the formation being drilled may be varied by `angularly ad- 1 justing the bit body 33 with respect to the shank 23. This relative adjustment may be accomplished by elevating thedrill pipev and its connected shank with respect to the bit 'body' 33 a suicient distance to cause the two clutch portions .3|V and 38 to be disconnected. `'Ihe shank, through the medium of the drill pipe, then may be rotated to a desired degree and lowered into its new position with respect to the bit body 33. As a result of such adjustments, the angle of attack of the cuttersmay be varied asdesired and the number of different relatively` adjusted positions will be controlled by the number of for application to the several wing cutters 62.-

The axis of the hole 6 and theupper'- threaded portion 48 of the shank are represented by the dash line 69. TheV axis of the shank pin and the bit body, with its cutters, isrepresented by the dash line 1|). It is apparent, therefore, that the axis of the bit is tilted relative to the axis of the hole.

It should not be necessary to explain in detail that the shank 41 and the bit body may be adjusted relative to each other by elevating the drill pipe and the shank to break the connection between the clutch parts 5| and 55 of these two elements and then rotating the drill pipe. This adjustment of the bit relative to the shank will ats providedon the clutch portions 3| and38.

Fig. 5 discloses another .modied form of 'rotary drilling unit. This unit also dilers from vthe preceding units by including a different typej of clutch and a diierent type of cutters. This unit includes a shank 41 which is provided with the conventional, reduced, threaded upper end 48`by means'- of which the unit may be connected to the drill collar carried by the'lower endjof a drill pipe, both of which are not shown. The

' shank is provided with a pin portion that includes a cylindrical its periphery an annular ball race 50. A clutch portion 5| also is provided asv aipart of the shank part 49, having formed in pin. This clutch portion constitutes the malems part of a cone clutch which isprovided with thev usual clutch leather .face 52. Y

The bit body 53 takes the form of a sleeve, the bore of which is shaped to provide a cylindrical portion 54, amale cone clutch portion 55, and a. threaded portion 56.A The'cylindrical portion 54 is formed with a retainer ball race 51 for receiving the circular series of balls' 58 that are positioned through the hole 59 normally clgsed by function to vary the angle. of attack of the vari-l ous cutters 62 and to vary the cutting action of the same while always maintaininga reserve in cutting edge area which may be successively brought into operative relation with respect to thebottom o f the hole until the effectiveness vof all of the edges has been lowered to a point where replacement is necessary or desirable.

In the units disclosed in Figs. 1 and 4, it is necessary, or at least very desirable, to stop the drilling operation when an adjustment is to be made between a drill shank and a bit body. With the unit illustrated in. Fig. 5, the drilling operation may be stopped when an adjustment'is to be made or an adjustment can be accomplished while drilling proceeds, When the latter type of adjustment is desired, the

leased from the body 53 and its bit a sufficient extent to permit slippagebetween the-clutch parts 5| and 55.l By varying the amount of slippage allowed, the incrementsof adjustment may be varied in any manner desired.

It is to be understood that, the-forms of this invention herewith shown and described are to 58 to permit the shank. 41 and bit body 53 to move relative to each other weight of the drill pipe, the drill collar, and the shank may be re' rotation thereby, a bit body member means for connecting said members so that the axis of the bit body member will be inclined to the axis of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will be operative, while others will be inoperative as a result of the inclination of the bit body member axis, means operating to rotate said bit body member with said shank member about the axis of the hole at a speed substantially equal to the rotative speed of the shank member, and means for effecting angular adjustments between-said two members to change the operative and inoperative relationship between the said cutting edges.

2.-In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe lfor rotation thereby, a bit body member, a telescopic connection between said members allowing for limited relative longitudinal movement, said bit body member being arranged with its axis inclined to the axis of a hole formed by the drill, means operative to rotate said bit body member with said shank member about the axis f the hole at a speed substantially equal to the rotative speed of the shank member, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will be operative while others will be inoperative as a result of the inclination of the bit body member axis, and means for effecting angular adjustment between said two members to change the inoperative and. operative relationship between the said cutting edges.

3. In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe, a bitbody member, means for connecting said members so that the axis of the bit body member will be inclined to the axis of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such a manner` that some of the said edges will be operative, while others will be inoperative as a result of the inclination of the bit body member axis, and means for eiecting angular adjustments between said two members to change the operative and inoperative relationship between the said cutting K edges, comprising cooperating clutch elements carried-by both members which are releasable to allow for and are connectable to prevent such adjustment.

4. In a rotary drill foroil wells, or the like, a shank member for attachment to a drill pipe, a bit body member, a telescopic connection between said members permitting relative longitudinal movement, means for limiting said relative longitudinal movement, said bit body member being arranged with its axis inclined to the axis of a hole formed by the-drill, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will be operative while others will be inoperative as a result of the inclination ofthe bit body member axis, and means for eiecting angular adjustments between said two members to change the operative and inoperative relationship between -the said cutting edges, comprising cooperating clutchelements carried by both members which are released and connected as a result of said limited relative longitudinal movement between the members.

5.. In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe, a

bit body` member, means for' connecting said members so that the axis of the bit body member will be inclined to the axsof a hole formed by the drill, a plurality of cutting'edges carried by the bit body member in such a manner that some of the said edges will be operative, while others will be inoperative as a result of the inclination of the bit body member axis,and means for effecting angular adjustments between said two members to change the operative and inoperative relationship between the said cutting edges, comprising cooperating sets of clutch teeth carried by both members which are releasable to allow for and are connectable to prevent such adjustment. y

, 6. In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe, a bit body member, means for connecting said members so that the axis of the bit body member will be inclined to the axis of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will be operative, while others will be inoperative as a result of the inclination of the bit body member axis, and means for effecting angular adjustments between said two members to vchange `the operative and inoperative relationship between the said cutting edges, comprising intertting pin and socket portions having cooperating lats carried by both members which are releasable to allow for and are connectable to prevent such adjustment.

7. In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe, a bit body member, a telescopic connection between said members allowing for limited relative longitudinal movement, said bit body member being arranged with its axis inclined to the axis of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will beoperative while others will be inoperative as a result of the inclination of the bit body member axis, and means for eiecting angular vadjustment between said two members to change the inoperative and operative relationship between the said cutting edges, comprising interfitting pin and socket portions having cooperating ilats formed as parts of the telescopic connection between said members, said pin and socket parts being released and connected as a result of said limited relative longitudinal movement between the members.

8. In a rotary drill forV oil wells, or the like, a shank member for attachment to a drill pipe, a

bit body member, meansfor connecting said members so that the axis of the bit body member will be inclined to the axis of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such a manner that some of the said edges will be operative, while others will be inoperative as a result of the inclination of the bit body member axis, and means for e1- fecting angular adjustments between said two members to change the operative and inoperative relationship between the said cutting edges, comprising a cone clutch having its cooperating parts carried by both members, and means for breaking the connection provided by said cone clutch parts when the shank. member is elevated with respect to the bit body member.

9. In a rotary drill for oil wells, or the like, a shank member adapted to be attached for move- A ment with a rotatable drill pipe, a bit body member rotating at the same speed as the shank member duringnormal drilling perfomance and having its axis inclined to the axis of the shank member, a plurality of cutting edges carried by of the bit body member axis, and means for effecting angular adjustment between said two members to change the operative and inoperative relationship between the said cutting edges.

10. In a rotary drill for oil wells, or the like, a shank member i'or attachment to a drill pipe for rotation thereby, a bit body member, means for connecting said members so that the axis of the bit body member will be inclined to the axis of the hole formed by the drill, a plurality of cutting edges carried by the bit body member in such manner that,"as a result of the inclination of the body member axis, some of the said cutting edges will carry a preponderance of the drilling load, means operating to rotate said bit body member with said shank member 'about the axis of the hole at a speed substantially equal to the rotative speed of the shank member, and means tween said cutting edges.

for eEecting angular-adjustments between said two members to change the load relationship bel I tween said cutting edges.

11. In a rotary drill for oil wells, or the like, a shank member for attachment to a drill pipe for rotation thereby, abit body member, means for 'connecting said members so that the axis of the bit body member will be inclined to the axis-of a hole formed by the drill, a plurality of cutting edges carried by the bit body member in such manner that some of the said edges will be inv of the shank member, and means for effecting angular adjustments between said two members to change,the eective drilling relationship be- J'Olim ZUBLIN. i 

